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Publisher: Elsevier   (Total: 3034 journals)

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Showing 1 - 200 of 3034 Journals sorted alphabetically
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 19, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 16, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 81, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 23, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 27, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 4)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 5, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 322, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 25, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription  
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 200, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 9, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription   (Followers: 1)
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 3, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 22, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 5, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 3)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 4, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 2)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 4, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 3)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 5)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 122, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 16, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 15, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 24, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 6, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 10, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 21, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 25, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 24, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 8, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 16, SJR: 0.223, h-index: 22)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 4)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Ecological Research     Full-text available via subscription   (Followers: 39, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 25, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 40, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 43, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 12)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 20, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 24)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 34, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 3, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 4)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 7, SJR: 0.764, h-index: 15)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Marine Biology     Full-text available via subscription   (Followers: 16, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 5, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 22)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 4)
Advances in Oncobiology     Full-text available via subscription   (Followers: 3)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15, SJR: 2.885, h-index: 45)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 7, SJR: 2.37, h-index: 73)
Advances in Pediatrics     Full-text available via subscription   (Followers: 21, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 13)
Advances in Pharmacology     Full-text available via subscription   (Followers: 15, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 7, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 8)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 19, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 58)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 2, SJR: 0.1, h-index: 2)
Advances in Space Research     Full-text available via subscription   (Followers: 337, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 8)
Advances in Surgery     Full-text available via subscription   (Followers: 6, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 29, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 15)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 13)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 43, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 5, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 309, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 4, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 7, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 393, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 30, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 38, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 1)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 50, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 5, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 9, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 5)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access  
Algal Research     Partially Free   (Followers: 8, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 5, SJR: 0.776, h-index: 35)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 6, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 46, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 5)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 3)
American Heart J.     Hybrid Journal   (Followers: 46, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 45, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 34, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 6, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 15, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 30, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 24, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 32, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 44, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 180, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 54, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 2)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 23, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 23, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 21, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 33, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 5)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 51, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 3)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 2, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 38, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 161, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 8, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 10)
Anesthésie & Réanimation     Full-text available via subscription  
Anesthesiology Clinics     Full-text available via subscription   (Followers: 21, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  
Animal Behaviour     Hybrid Journal   (Followers: 151, SJR: 1.907, h-index: 126)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5, SJR: 1.151, h-index: 83)
Animal Reproduction Science     Hybrid Journal   (Followers: 5, SJR: 0.711, h-index: 78)
Annales d'Endocrinologie     Full-text available via subscription   (SJR: 0.394, h-index: 30)
Annales d'Urologie     Full-text available via subscription  
Annales de Cardiologie et d'Angéiologie     Full-text available via subscription   (SJR: 0.177, h-index: 13)
Annales de Chirurgie de la Main et du Membre Supérieur     Full-text available via subscription  
Annales de Chirurgie Plastique Esthétique     Full-text available via subscription   (Followers: 2, SJR: 0.354, h-index: 22)
Annales de Chirurgie Vasculaire     Full-text available via subscription   (Followers: 1)

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Journal Cover Aeolian Research
  [SJR: 0.973]   [H-I: 22]   [5 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1875-9637
   Published by Elsevier Homepage  [3034 journals]
  • Ground robotic measurement of aeolian processes
    • Authors: Feifei Qian; Douglas Jerolmack; Nicholas Lancaster; George Nikolich; Paul Reverdy; Sonia Roberts; Thomas Shipley; R. Scott Van Pelt; Ted M. Zobeck; Daniel E. Koditschek
      Pages: 1 - 11
      Abstract: Publication date: August 2017
      Source:Aeolian Research, Volume 27
      Author(s): Feifei Qian, Douglas Jerolmack, Nicholas Lancaster, George Nikolich, Paul Reverdy, Sonia Roberts, Thomas Shipley, R. Scott Van Pelt, Ted M. Zobeck, Daniel E. Koditschek
      Models of aeolian processes rely on accurate measurements of the rates of sediment transport by wind, and careful evaluation of the environmental controls of these processes. Existing field approaches typically require intensive, event-based experiments involving dense arrays of instruments. These devices are often cumbersome and logistically difficult to set up and maintain, especially near steep or vegetated dune surfaces. Significant advances in instrumentation are needed to provide the datasets that are required to validate and improve mechanistic models of aeolian sediment transport. Recent advances in robotics show great promise for assisting and amplifying scientists’ efforts to increase the spatial and temporal resolution of many environmental measurements governing sediment transport. The emergence of cheap, agile, human-scale robotic platforms endowed with increasingly sophisticated sensor and motor suites opens up the prospect of deploying programmable, reactive sensor payloads across complex terrain in the service of aeolian science. This paper surveys the need and assesses the opportunities and challenges for amassing novel, highly resolved spatiotemporal datasets for aeolian research using partially-automated ground mobility. We review the limitations of existing measurement approaches for aeolian processes, and discuss how they may be transformed by ground-based robotic platforms, using examples from our initial field experiments. We then review how the need to traverse challenging aeolian terrains and simultaneously make high-resolution measurements of critical variables requires enhanced robotic capability. Finally, we conclude with a look to the future, in which robotic platforms may operate with increasing autonomy in harsh conditions. Besides expanding the completeness of terrestrial datasets, bringing ground-based robots to the aeolian research community may lead to unexpected discoveries that generate new hypotheses to expand the science itself.

      PubDate: 2017-05-13T12:15:26Z
      DOI: 10.1016/j.aeolia.2017.04.004
      Issue No: Vol. 27 (2017)
       
  • Evaluating the effectiveness of agricultural mulches for reducing
           post-wildfire wind erosion
    • Authors: P.R. Robichaud; J. Jennewein; B.S. Sharratt; S.A. Lewis; R.E. Brown
      Pages: 13 - 21
      Abstract: Publication date: August 2017
      Source:Aeolian Research, Volume 27
      Author(s): P.R. Robichaud, J. Jennewein, B.S. Sharratt, S.A. Lewis, R.E. Brown
      Post-wildfire soil erosion can be caused by water or aeolian processes, yet most erosion research has focused on predominantly water-driven erosion. This study investigates the effectiveness of three agricultural mulches, with and without a tackifier, on aeolian sediment transport processes. A wind tunnel was used to simulate post-wildfire wind erosion at three wind speeds (6, 11 and 18ms−1). Shallow trays containing soil collected after a wildfire were treated with chopped rice, wheat or chopped wheat mulch; mulch treatments were also compounded with liquid treatments, tackifier to water ratios of 1:6, 1:3 and water. The mulch treatments were generally easily moved at all wind speeds with cover reductions greater than 90% at the highest wind speed. As expected, sediment loss was greatest for the bare soil treatment, ranging from 6.5gm−2 at the lowest wind speed which increases to 6258gm−2 at the highest wind speed. Adding wheat or chopped wheat mulch significantly reduced sediment loss by an order or magnitude (698 and 298gm−2, respectively) at the highest wind speed. Adding chopped rice straw reduced sediment loss by a half to 3573gm−2 at the highest wind speed, but the effect was not significant due to mobilization of the mulch. The most effective sediment loss mitigation was achieved with liquid tackifier treatments when applied to bare soil and when compounded with various mulch treatments, particularly at the highest wind speed. These results may aid management decisions when mitigating aeolian sediment transport after wildfires.

      PubDate: 2017-06-02T12:30:50Z
      DOI: 10.1016/j.aeolia.2017.05.001
      Issue No: Vol. 27 (2017)
       
  • Intensity and degree of segregation in bimodal and multimodal grain size
           distributions
    • Authors: Itzhak Katra; Hezi Yizhaq
      Pages: 23 - 34
      Abstract: Publication date: August 2017
      Source:Aeolian Research, Volume 27
      Author(s): Itzhak Katra, Hezi Yizhaq
      The commonly used grain size analysis technique which applies moments (sorting, skewness and kurtosis) is less useful in the case of sediments with bimodal size distributions. Herein we suggest a new simple method for analyzing the degree of grain size segregation in sand-sized sediment that has clear bimodal size distributions. Two main features are used to characterize the bimodal distribution: grain diameter segregation, which is the normalized difference between coarse and fine grain diameters, and the frequency segregation which is the normalized difference in frequencies between two modes. The new defined indices can be calculated from frequency plot curves and can be graphically represented on a two dimensional coordinate system showing the dynamical aspects of the size distribution. The results enable comparison between granular samples from different locations and/or times to shed new light on the dynamic processes involved in grain size segregation of sediments. We demonstrate here the use of this method to analyze bimodal distributions of aeolian granular samples mostly from aeolian megaripples. Six different aeolian cases were analyzed to highlight the method’s applicability, which is relevant to wide research themes in the Earth and environmental sciences, and can furthermore be easily adapted to analyze polymodal grain size distributions.

      PubDate: 2017-06-07T12:34:10Z
      DOI: 10.1016/j.aeolia.2017.05.002
      Issue No: Vol. 27 (2017)
       
  • Editorial Introduction: Fourth Planetary Dunes Workshop Special Issue
    • Authors: Matthew Chojnacki; Matt W. Telfer
      Pages: 1 - 3
      Abstract: Publication date: June 2017
      Source:Aeolian Research, Volume 26
      Author(s): Matthew Chojnacki, Matt W. Telfer


      PubDate: 2017-06-17T03:25:04Z
      DOI: 10.1016/j.aeolia.2017.05.003
      Issue No: Vol. 26 (2017)
       
  • Aeolian sand transport and aeolian deposits on Venus: A review
    • Authors: Mikhail A. Kreslavsly; Nataliya V. Bondarenko
      Pages: 29 - 46
      Abstract: Publication date: June 2017
      Source:Aeolian Research, Volume 26
      Author(s): Mikhail A. Kreslavsly, Nataliya V. Bondarenko
      We review the current state of knowledge about aeolian sand transport and aeolian bedforms on planet Venus. This knowledge is limited by lack of observational data. Among the four planetary bodies of the Solar System with sufficient atmospheres in contact with solid surfaces, Venus has the densest atmosphere; the conditions there are transitional between those for terrestrial subaerial and subaqueous transport. The dense atmosphere causes low saltation threshold and short characteristic saltation length, and short scale length of the incipient dunes. A few lines of evidence indicate that the typical wind speeds exceed the saltation threshold; therefore, sand transport would be pervasive, if sand capable of saltation is available. Sand production on Venus is probably much slower than on the Earth; the major terrestrial sand sinks are also absent, however, lithification of sand through sintering is expected to be effective under Venus’ conditions. Active transport is not detectable with the data available. Aeolian bedforms (transverse dunes) resolved in the currently available radar images occupy a tiny area on the planet; however, indirect observations suggest that small-scale unresolved aeolian bedforms are ubiquitous. Aeolian transport is probably limited by sand lithification causing shortage of saltation-capable material. Large impact events likely cause regional short-term spikes in aeolian transport by supplying a large amount of sand-size particles, as well as disintegration and activation of older indurated sand deposits. The data available are insufficient to understand whether the global aeolian sand transport occurs or not. More robust knowledge about aeolian transport on Venus is essential for future scientific exploration of the planet, in particular, for implementation and interpretation of geochemical studies of surface materials. High-resolution orbital radar imaging with local to regional coverage and desirable interferometric capabilities is the most effective way to obtain essential new knowledge about aeolian transport on Venus.

      PubDate: 2017-06-17T03:25:04Z
      DOI: 10.1016/j.aeolia.2016.06.001
      Issue No: Vol. 26 (2017)
       
  • Surface slope effects for ripple orientation on sand dunes in López
           crater, Terra Tyrrhena region of Mars
    • Authors: James R. Zimbelman; Molly B. Johnson
      Pages: 57 - 62
      Abstract: Publication date: June 2017
      Source:Aeolian Research, Volume 26
      Author(s): James R. Zimbelman, Molly B. Johnson
      Ripple orientations on small sand dunes (dunes lacking substantial slip faces) at widely distributed sites across Mars have been documented using High Resolution Imaging Science Experiment (HiRISE) images, in an effort to determine the last formative aeolian sediment transport direction experienced at these locations. Howard (1977) used field measurements and first principles to derive an expression for determining how much the surface slope on a sand dune deflects the orientation of sand ripples with respect to the formative wind direction. A Digital Terrain Model derived from stereo HiRISE images was used to assess the potential deflection of ripples on sand dunes on the floor of López crater on Mars. Three-quarters of the area covered by sand dunes within the DTM has a surface slope <10°, where deflection angles are expected to be <17° (a value that should not pose a major issue for comparison to model-derived winds); such surface slopes are typical of small sand dunes on Mars that lack large slip faces. Sand ripples therefore should be good indicators of the most recent sand-transporting winds that have blown across sand dunes on Mars, as long as areas on or very near to slip faces are avoided.

      PubDate: 2017-06-17T03:25:04Z
      DOI: 10.1016/j.aeolia.2016.08.007
      Issue No: Vol. 26 (2017)
       
  • Migrating meter-scale bedforms on Martian dark dunes: Are terrestrial
           aeolian ripples good analogues'
    • Authors: David A. Vaz; S. Silvestro; Pedro T.K. Sarmento; M. Cardinale
      Pages: 101 - 116
      Abstract: Publication date: June 2017
      Source:Aeolian Research, Volume 26
      Author(s): David A. Vaz, S. Silvestro, Pedro T.K. Sarmento, M. Cardinale
      Using automatic bedform mapping, principal component analysis and clustering we present a multiscale morphodynamic survey of dunes and meter-scale ripples on Herschel crater, Mars. The main purpose of this study is to assess if the morphology and temporal evolution of Martian meter-scale ripples is comparable to the morphodynamic characteristics of terrestrial aeolian impact ripples. We demonstrate that the spatial variations of the mapped dune patterns are correlated with substrate topography, which also influences the spatial distribution of the height and celerity of dunes’ slipfaces. This topographic forcing is also patent on the spatial distribution of the ripples, thus proving that a multiscale coupling of active bedforms exists on Herschel under the present surface conditions. We found that Martian meter-scale ripples are morphologically distinct from terrestrial aeolian ripples, presenting a lower degree of straightness. Only ∼3% of the mapped ripples can be considered sinuous or straight bedforms. Moreover, we conclude that this two-dimensional sub-population is restricted to well define dune settings, where factors that promote the elongation of the meter-scale ripples were identified: gravity transport on higher slopes, bedform obliquity and flow convergence on the leeward side of dunes. We also report that the different sets of ripples that were mapped and segmented do not present a transverse migration. Therefore we conclude that terrestrial aeolian ripples are not good analogues for Martian meter-scale bedforms, either in terms of morphology or dynamic evolution.

      PubDate: 2017-06-17T03:25:04Z
      DOI: 10.1016/j.aeolia.2016.08.003
      Issue No: Vol. 26 (2017)
       
  • Sedimentary differentiation of aeolian grains at the White Sands National
           Monument, New Mexico, USA
    • Authors: Lori K. Fenton; Janice L. Bishop; Sara King; Barbara Lafuente; Briony Horgan; David Bustos; Philippe Sarrazin
      Pages: 117 - 136
      Abstract: Publication date: June 2017
      Source:Aeolian Research, Volume 26
      Author(s): Lori K. Fenton, Janice L. Bishop, Sara King, Barbara Lafuente, Briony Horgan, David Bustos, Philippe Sarrazin
      Gypsum (CaSO4·2H2O) has been identified as a major component of part of Olympia Undae in the northern polar region of Mars, along with the mafic minerals more typical of Martian dune fields. The source and age of the gypsum is disputed, with the proposed explanations having vastly different implications for Mars’ geological history. Furthermore, the transport of low density gypsum grains relative to and concurrently with denser grains has yet to be investigated in an aeolian setting. To address this knowledge gap, we performed a field study at White Sands National Monument (WSNM) in New Mexico, USA. Although gypsum dominates the bulk of the dune field, a dolomite-rich [CaMg(CO3)2] transport pathway along the northern border of WSNM provides a suitable analog site to study the transport of gypsum grains relative to the somewhat harder and denser carbonate grains. We collected samples along the stoss slope of a dune and on two coarse-grained ripples at the upwind margin of the dune field where minerals other than gypsum were most common. For comparison, additional samples were taken along the stoss slope of a dune outside the dolomite transport pathway, in the center of the dune field. Visible and near-infrared (VNIR), X-ray powder diffraction (XRD), and Raman analyses of different sample size fractions reveal that dolomite is only prevalent in grains larger than ∼1mm. Other minerals, most notably calcite, are also present in smaller quantities among the coarse grains. The abundance of these coarse grains, relative to gypsum grains of the same size, drops off sharply at the upwind margin of the dune field. In contrast, gypsum dominated the finer fraction (<∼1 mm) at all sample sites, displaying no spatial variation. Estimates of sediment fluxes indicate that, although mineralogical differentiation of wind-transported grains occurs gradually in creep, the process is much more rapid when winds are strong enough to saltate the ⩾1mm grains. The observed grain segregation is consistent with the WSNM dune field formative friction velocity (0.39m/s) proposed by Jerolmack et al. (2011): winds significantly weaker than this value would not lift the large grains into differentiation-inducing saltation, whereas the observed differentiated trend would be obliterated by significantly stronger winds. When applied to Olympia Undae, a similar sediment flux analysis suggests that the strongest winds modeled by the Mars Climate Database (MCD) are consistent with the observed concentration of gypsum at dune crests. Density-driven differentiation in transport should not influence sediment fluxes of finer grains (<1mm) as strongly on Earth, suggesting that the high ratio of fine gypsum grains to other minerals at WSNM is caused by a relatively high production and/or abrasion rate of gypsum sand. The observed preferential transport of coarse-grained gypsum in the dune field conceals a broader range of coarse-grained minerals present on Alkali Flat, contributing to the problem that mineralogy determined through both remote sensing of dune fields and analysis of dune foresets does not fully represent that of the source regions. Unlike quartz, the concentration of gypsum in WSNM occurs not because it is more resistant to weathering and erosion than other minerals, but rather because it is more readily produced (in the case of finer grains) and transported (in the case of coarser grains) than other minerals present in the region.

      PubDate: 2017-06-17T03:25:04Z
      DOI: 10.1016/j.aeolia.2016.05.001
      Issue No: Vol. 26 (2017)
       
  • Eolianite and coquinite as evidence of MIS 6 and 5, NW Black Sea coast,
           Turkey
    • Authors: Ahmet Evren Erginal; Nafiye Güneç Kıyak; Hamit Haluk Selim; Mustafa Bozcu; Muhammed Zeynel Öztürk; Yunus Levent Ekinci; Alper Demirci; Elmas Kırcı Elmas; Tuğba Öztürk; Çağlar Çakır; Mustafa Karabıyıkoğlu
      Pages: 1 - 9
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Ahmet Evren Erginal, Nafiye Güneç Kıyak, Hamit Haluk Selim, Mustafa Bozcu, Muhammed Zeynel Öztürk, Yunus Levent Ekinci, Alper Demirci, Elmas Kırcı Elmas, Tuğba Öztürk, Çağlar Çakır, Mustafa Karabıyıkoğlu
      This paper discusses the implications of a lowstand carbonate eolianite and overlying transgressive sequence of coquinite at Şile on the Turkish Black Sea coast based on composition, depositional characteristics and optical age estimations. The cross-bedded eolianite is a mixed ooid quartz grainstone in composition, yielding a depositional age matching MIS 6. It formed at the backshore of the paleobeach with the supply of sediment the from the beach face and offering insights into the drift of mixed shallow marine carbonates and siliciclastics together with radial ooids by onshore winds from a subaerially exposed high- to low-energy ooid shoals and oolitic sand complexes which developed parallel to the shoreline on the shallow shelf margin. During this lowstand, a low-relief dune retaining a record of opposing paleowind directions than that of prevalent northeasterly winds of today appears to have been lithified to form dune rock (aeolinite) under drier conditions compared to the present. Coinciding with MIS 5e, shallow marine coquina beds resting unconformably on the eolianite indicate the occurrence of the Mediterranean transgression during the last interglacial, as confirmed by benthic foraminifera within the high-salinity tolerant coquina shells.

      PubDate: 2017-02-17T10:08:03Z
      DOI: 10.1016/j.aeolia.2017.01.004
      Issue No: Vol. 25 (2017)
       
  • A wind tunnel study of the aerodynamic and sand trapping properties of
           porous mesh 3-dimensional roughness elements
    • Authors: J.A. Gillies; W.G. Nickling; G. Nikolich; V. Etyemezian
      Pages: 23 - 35
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): J.A. Gillies, W.G. Nickling, G. Nikolich, V. Etyemezian
      The aerodynamic drag properties and sand trapping effectiveness of porous roughness elements constructed of wire mesh with two geometries, cube/rectangular cylinder and round cylinder were evaluated in a wind tunnel study. Porosity of the mesh was 0.525. Volumetric porosity and permeability were systematically changed by nesting similar shaped but smaller sized forms within the largest forms for both shapes. Drag curves for both forms show dependence on Reynolds number to 70,000, due to the creation of complex transitional flow conditions in different zones within the forms. Length of sand deposits in the lee of the elements scale with permeability of the form and the trapping efficiency for particles within the forms scales with the cumulative area of the surfaces perpendicular to the directions of air flow. The cube/rectangular cylinder form was more effective at trapping sand than the round cylinder forms for the same saltation flux. The demonstrated effect of porosity and cumulative mesh area on aerodynamic drag and sand trapping effectiveness argues convincingly that porous elements have a greater potential than solid elements for modulating the sand flux to a higher degree than solid elements when used in large spatial arrays to control wind erosion.

      PubDate: 2017-02-17T10:08:03Z
      DOI: 10.1016/j.aeolia.2017.02.001
      Issue No: Vol. 25 (2017)
       
  • Laser particle counter validation for aeolian sand transport measurements
           using a highspeed camera
    • Authors: Leonardo Duarte-Campos; Kathelijne M. Wijnberg; Loreto Oyarte-Gálvez; Suzanne J.M.H. Hulscher
      Pages: 37 - 44
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Leonardo Duarte-Campos, Kathelijne M. Wijnberg, Loreto Oyarte-Gálvez, Suzanne J.M.H. Hulscher
      Measuring aeolian sand transport rates in the field has been a long-standing challenge. In this paper, we present the results of a laboratory experiment to test the ability of a laser particle counter sensor (Wenglor) to accurately count sand grains of various grain size classes and stainless steel beads. We compared the count data collected by the Wenglor with images from a Highspeed camera which revealed the actual number of grains passing the laser beam. A Silicon photodiode was used to record the laser intensity reduction induced by the sand grain passage through the laser beam to derive the minimal necessary reduction for the Wenglor to count grains. For the two possible settings of the Wenglor, i.e., Minimal Teach-in or Normal Teach-in, a minimum of 18% and 78% blocking of the laser beam was required for recording a count. This implies that the minimum grain size that can be observed by the Wenglor is 210 ± 3 μ m and 495 ± 10 μ m for the two settings respectively, which is considerably coarser than previously assumed. Due to the non-uniform power distribution of the laser sensor intensity, at the detection limit of 210μm, only grains passing through the centre of the beam will be counted.

      PubDate: 2017-02-24T10:39:08Z
      DOI: 10.1016/j.aeolia.2017.02.002
      Issue No: Vol. 25 (2017)
       
  • Complexity confers stability: Climate variability, vegetation response and
           sand transport on longitudinal sand dunes in Australia’s deserts
    • Authors: Paul P. Hesse; Matt W. Telfer; Will Farebrother
      Pages: 45 - 61
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Paul P. Hesse, Matt W. Telfer, Will Farebrother
      The relationship between antecedent precipitation, vegetation cover and sand movement on sand dunes in the Simpson and Strzelecki Deserts was investigated by repeated (up to four) surveys of dune crest plots (≈25×25m) over a drought cycle (2002–2012) in both winter (low wind) and spring (high wind). Vegetation varied dramatically between surveys on vegetated and active dune crests. Indices of sand movement had significant correlations with vegetation cover: the depth of loose sand has a strong inverse relationship with crust (cyanobacterial and/or physical) while the area covered by ripples has a strong inverse relationship with the areal cover of vascular plants. However, the relationship between antecedent rainfall and vegetation cover was found to be complex. We tentatively identify two thresholds; (1) >10mm of rainfall in the preceding 90days leads to rapid and near total cover of crust and/or small plants <50cm tall, and (2) >400mm of rainfall in the preceding three years leads to higher cover of persistent and longer-lived plants >50cm tall. These thresholds were used to predict days of low vegetation cover on dune crests. The combination of seasonality of predicted bare-crest days, potential sand drift and resultant sand drift direction explains observed patterns of sand drift on these dunes. The complex vegetation and highly variable rainfall regime confer meta-stability on the dunes through the range of responses to different intervals of antecedent rainfall and non-linear growth responses. This suggests that the geomorphic response of dunes to climate variation is complex and non-linear.

      PubDate: 2017-02-24T10:39:08Z
      DOI: 10.1016/j.aeolia.2017.02.003
      Issue No: Vol. 25 (2017)
       
  • Loess deposits of the upper Hanjiang River valley, south of Qinling
           Mountains, China: Implication for the pedogenic dynamics controlled by
           paleomonsoon climate evolution
    • Authors: Peini Mao; Jiangli Pang; Chunchang Huang; Xiaochun Zha; Yali Zhou; Yongqiang Guo
      Pages: 63 - 77
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Peini Mao, Jiangli Pang, Chunchang Huang, Xiaochun Zha, Yali Zhou, Yongqiang Guo
      Aeolian deposits in the Chinese Loess Plateau (CLP) provide a detailed archive for reconstructing the pedogenic intensity as well as the East Asian monsoon climate change. However, study on the loess in the upper Hanjiang River valley, south of Qinling Mountains has seldom been comprehensively reported. Located at the transition zone between temperate and subtropical monsoon climate, the study area is more sensitive to the climate change. In this paper, three loess-paleosol profiles at the first terrace of the upper Hanjiang River were studied in detail. High-resolution investigations, including field observations, optically stimulated luminescence (OSL) dating, and measurements of magnetic susceptibility (MS), grain-size (GS), color variation, loss-on-ignition (LOI) and chemical elements were carried out. The results show that the stratigraphic sequences, in order from the top to the bottom, are topsoil (TS), recent loess (L0), paleosol (S0), transitional loess (Lt), Malan loess (L1) and fluvial deposits (T1-al). The pedogenic intensity varies significantly in different layers and presents such a tendency of S0 >L0 >Lt>L1. This indicates four distinct stages in the paleoclimate evolution: a cold-dry period (55.0–11.5ka B.P.); a phase of gradual transition to warm-wet (11.5–8.5ka B.P.); the maximum warm-wet period (8.5–3.0ka B.P.); and a phase of gradually shifting to cool-dry (3.0–0.0ka B.P.). The climate change trends are similar with the loess records from the CLP and the stalagmite and peat records in southern China. But the paleosol development in the study is probably a better indicator of the strength of summer monsoon climate change during the mid-Holocene Climatic Optimum. This study also provides basic data for exploring the pedogenesis and climate differences in the East Asian monsoon climate zones.

      PubDate: 2017-03-28T10:58:48Z
      DOI: 10.1016/j.aeolia.2017.03.001
      Issue No: Vol. 25 (2017)
       
  • Suspended dust particle characteristics during an sandstorm on 29 February
           2008 in Minqin area, China
    • Authors: KeJie Zhan; ShiZeng Liu; ZiHui Yang; ETian Fang; LanPing Zhou; QiangQiang Wang; ShuJiang Guo; JianHui Zhang; Ning Huang
      Pages: 79 - 86
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): KeJie Zhan, ShiZeng Liu, ZiHui Yang, ETian Fang, LanPing Zhou, QiangQiang Wang, ShuJiang Guo, JianHui Zhang, Ning Huang
      Aeolian dust is one of the main aerosols in the troposphere, and plays an important role in the Earth’s climate system. In this study, detailed meteorological conditions and dust particle diameters were measured at three sites with different landscape characteristics in the Minqin oasis area of northwest China, on 29 February 2008. We show that as dust storms progressed through the desert into the oasis, variation in the character of the underlying land surface not only influenced the wind profile by modifying the frictional velocity of air (U∗), aerodynamic roughness length (Z0), horizontal sediment flux, and dust concentration of the near surface sublayer (1–49m), but it also changed the vertical structure of the aeolian sediment transport pattern. The particle size frequency distributions at three distinct sites were all unimodal, comprising a large number of aeolian dust particles with sizes less than 63μm (more than 65%). During transport, dust particle populations shifted to smaller sizes. Clearly, the influence of landform, windbreaks, and vegetation cover on horizontal sand-dust flux decreased with height as well as increasing particle size, with smaller aeolian particles being more easily captured by windbreaks, and vegetation.

      PubDate: 2017-04-18T11:55:51Z
      DOI: 10.1016/j.aeolia.2017.04.002
      Issue No: Vol. 25 (2017)
       
  • Comments on ‘Influence of measurement uncertainties on fractional
           solubility of iron in mineral aerosols over the oceans’ Aeolian Research
           22, 85–92
    • Authors: Robert Raiswell; Jon R. Hawkings; Liane G. Benning; Samuel Albani; Natalie Mahowald
      Pages: 123 - 125
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Robert Raiswell, Jon R. Hawkings, Liane G. Benning, Samuel Albani, Natalie Mahowald


      PubDate: 2017-04-18T11:55:51Z
      DOI: 10.1016/j.aeolia.2017.03.003
      Issue No: Vol. 25 (2017)
       
  • Magnetic susceptibility of surface soils in the Mu Us Desert and its
           environmental significance
    • Authors: Xiaokang Liu; Ruijie Lu; Zhiqiang Lü; Jing Du; Feifei Jia; Tengfei Li; Lu Chen; Yongqiu Wu
      Pages: 127 - 134
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Xiaokang Liu, Ruijie Lu, Zhiqiang Lü, Jing Du, Feifei Jia, Tengfei Li, Lu Chen, Yongqiu Wu
      Magnetic susceptibility has been widely used as a climatic proxy in paleoclimatic research. In arid and semi-arid regions, the magnetic properties of modern surface soil are significantly influenced by precipitation. This is demonstrated by observed positive correlations between percentage frequency-dependent magnetic susceptibility (χfd%), which reflects the presence of fine-grained (superparamagnetic, SP) grains produced during weathering and pedogenesis, and regional mean annual precipitation (MAP). To further investigate this relationship, we measured the magnetic properties of 104 surface soil samples collected along two transects (AA and BB) spanning a rainfall gradient across the Mu Us Desert in northern China. There were no systematic trends in magnetic properties along transect BB; the χfd% values remained relatively low and stable, probably reflecting weak pedogenesis and the domination of the magnetic properties by lithology. In contrast, along transect AA there was a significant positive correlation (p<0.01) between χfd% and regional MAP. From this relationship, we developed a transfer function (P=274.1+1424.4×χfd%) and used it to produce quantitative estimates of paleo-precipitation within three Holocene aeolian sections located in the southern the modern Mu Us Desert. The results show that the variations of reconstructed precipitation are consistent with those of lithological properties, and they also confirm previous conclusions that paleosol development in the study area is dominated by precipitation. Overall the results further demonstrate the feasibility of using frequency-dependent magnetic susceptibility to quantitatively reconstruct regional paleo-precipitation, including within a geographically diverse desert area. In addition, they provide an improved understanding of the main sand provenance in Mu Us Desert.

      PubDate: 2017-04-25T12:01:32Z
      DOI: 10.1016/j.aeolia.2017.04.003
      Issue No: Vol. 25 (2017)
       
  • Application of a modeling approach to designate soil and soil organic
           carbon loss to wind erosion on long-term monitoring sites (BDF) in
           Northern Germany
    • Authors: Rainer Nerger; Roger Funk; Eckhard Cordsen; Nicola Fohrer
      Pages: 135 - 147
      Abstract: Publication date: April 2017
      Source:Aeolian Research, Volume 25
      Author(s): Rainer Nerger, Roger Funk, Eckhard Cordsen, Nicola Fohrer
      Soil organic carbon (SOC) loss is a serious problem in maize monoculture areas of Northern Germany. Sites of the soil monitoring network (SMN) “Boden-Dauerbeobachtung” show long-term soil and SOC losses, which cannot be explained by conventional SOC balances nor by other non-Aeolian causes. Using a process-based model, the main objective was to determine whether these losses can be explained by wind erosion. In the long-term context of 10years, wind erosion was not measured directly but often observed. A suitable estimation approach linked high-quality soil/farming monitoring data with wind erosion modeling results. The model SWEEP, validated for German sandy soils, was selected using 10-minute wind speed data. Two similar local SMN study sites were compared, however, site A was characterized by high SOC loss and often affected by wind erosion, while the reference site B was not. At site A soil mass and SOC stock decreased by 49.4 and 2.44kgm−2 from 1999 to 2009. Using SWEEP, a total soil loss of 48.9kgm−2 resulted for 16 erosion events (max. single event 12.6kgm−2). A share of 78% was transported by suspension with a SOC enrichment ratio (ER) of 2.96 (saltation ER 0.98), comparable to the literature. At the reference site measured and modeled topsoil losses were minimal. The good agreement between monitoring and modeling results suggested that wind erosion caused significant long-term soil and SOC losses. The approach uses results of prior studies and is applicable to similar well-studied sites without other noteworthy SOC losses.

      PubDate: 2017-05-02T12:06:41Z
      DOI: 10.1016/j.aeolia.2017.03.006
      Issue No: Vol. 25 (2017)
       
  • Understanding dust emission in the Bodélé region by extracting locally
           mobilized dust aerosols from satellite Aerosol Optical Depth data using
           principal component analysis
    • Authors: Sagar Prasad Parajuli; Zong-Liang Yang
      Pages: 105 - 113
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Sagar Prasad Parajuli, Zong-Liang Yang
      Despite the increasing availability of satellite and ground-based Aerosol Optical Depth (AOD) data, their application in dust modeling is limited because these data do not differentiate locally mobilized dust from remotely advected dust and other aerosols. In this work, we extract the locally mobilized Dust Optical Depth (DOD) in the Bodélé region from historical AOD data through a principal component analysis of wind speed and AOD time series (2003–2012). Principal component analysis effectively identifies the correlated signature between wind speed and AOD making it possible to separate the dust component from AOD data. Using the reconstructed DOD, we then study the effect of key environmental variables, namely wind speed, soil moisture, soil temperature, vegetation, and boundary layer height on dust emission. Results show that all of these environmental variables are significantly correlated with the reconstructed DOD indicating their association with the dust emission process. The extraction technique described in this study can be extended to regional and global scales to identify the dust sources which are not adequately represented in regional and global dust models.

      PubDate: 2017-01-09T03:51:16Z
      DOI: 10.1016/j.aeolia.2017.01.001
      Issue No: Vol. 24 (2017)
       
  • Sensitivity of WRF-chem predictions to dust source function specification
           in West Asia
    • Authors: Seyed Omid Nabavi; Leopold Haimberger; Cyrus Samimi
      Pages: 115 - 131
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Seyed Omid Nabavi, Leopold Haimberger, Cyrus Samimi
      Dust storms tend to form in sparsely populated areas covered by only few observations. Dust source maps, known as source functions, are used in dust models to allocate a certain potential of dust release to each place. Recent research showed that the well known Ginoux source function (GSF), currently used in Weather Research and Forecasting Model coupled with Chemistry (WRF-chem), exhibits large errors over some regions in West Asia, particularly near the IRAQ/Syrian border. This study aims to improve the specification of this critical part of dust forecasts. A new source function based on multi-year analysis of satellite observations, called West Asia source function (WASF), is therefore proposed to raise the quality of WRF-chem predictions in the region. WASF has been implemented in three dust schemes of WRF-chem. Remotely sensed and ground-based observations have been used to verify the horizontal and vertical extent and location of simulated dust clouds. Results indicate that WRF-chem performance is significantly improved in many areas after the implementation of WASF. The modified runs (long term simulations over the summers 2008–2012, using nudging) have yielded an average increase of Spearman correlation between observed and forecast aerosol optical thickness by 12–16 percent points compared to control runs with standard source functions. They even outperform MACC and DREAM dust simulations over many dust source regions. However, the quality of the forecasts decreased with distance from sources, probably due to deficiencies in the transport and deposition characteristics of the forecast model in these areas.

      PubDate: 2017-01-16T04:41:38Z
      DOI: 10.1016/j.aeolia.2016.12.005
      Issue No: Vol. 24 (2017)
       
  • A quantitative evaluation of the 3–8 July 2009 Shamal dust storm
    • Authors: Mehdi Hamidi; Mohammad Reza Kavianpour; Yaping Shao
      Pages: 133 - 143
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Mehdi Hamidi, Mohammad Reza Kavianpour, Yaping Shao
      In this paper, a quantitative evaluation of the severe dust storm which occurred in the Middle East during 3–8 July 2009 is presented. The quantification is based on the numerical simulation using the WRF/Chem-D model which has been verified and calibrated for the Middle East region. It is found that, during the 3–8 July 2009 event, more than 9.67Tg dust were emitted from the study area and the maximum simulated dust emission rate is 540 (μgm−2 s−1). The west of Iraq, east of Syria and northwest of Jordan (Al-Nafud desert and western Euphrates alluvial plain) are found to be the most active areas of dust emission, contributing much to the dust emission from the Middle East region. In this study, more that 60% of dust particles were emitted from these areas and less than 10% were emitted from Iran dust sources. About 21% of the deposited dust was deposited in Iran land, while 79% in other parts of the study area. The dust load in the study area was estimated to be more than 0.3gm−2. The residence time of dust in the atmosphere was 6.2days over the study area, 7.8days over Iran and 6days over other parts. The simulation results exhibit that Iran contribution in emission rate in the study area is much lower than its contribution in dust deposition and residence time and the conclusion of this study can demonstrate the necessity of forming cooperation for suppressing the severe dust events.

      PubDate: 2017-01-16T04:41:38Z
      DOI: 10.1016/j.aeolia.2016.12.004
      Issue No: Vol. 24 (2017)
       
  • A new depositional model for sand-rich loess on the Buckley Flats outwash
           plain, northwestern Lower Michigan
    • Authors: Kelsey E. Nyland; Randall J. Schaetzl; Anthony Ignatov; Bradley A. Miller
      Abstract: Publication date: Available online 7 June 2017
      Source:Aeolian Research
      Author(s): Kelsey E. Nyland, Randall J. Schaetzl, Anthony Ignatov, Bradley A. Miller
      Loess was first studied in Michigan on the Buckley Flats, where outwash, overlain by ≈70cm of loamy sediment, was originally interpreted as loess mixed with underlying sands. This paper re-evaluates this landscape through a spatial analysis of data from auger samples and soil pits. To better estimate the loamy sediment’s initial textures, we utilized “filtered” laser diffraction data, which remove much of the coarser sand data. Textures of filtered silt data for the loamy sediment are similar to loess. The siltiest soils are found in the low-relief, central part of the Flats. Spatial analyses revealed that many silt fractions are nearly uniformly distributed, suggesting that the loess was not derived from a single source. The previous depositional model for the loamy mantle relied on loessfall followed by pedoturbation, but does not explain (1) the variation in sand contents across the Flats, or (2) the abrupt contact below the loamy mantle. This contact suggests that the outwash was frozen when the sediments above were deposited. Deep gullies at the western margins of the Flats were likely cut as permafrost facilitated runoff. Our new model for the origin of the loamy mantle suggests that the sands on the uplands were generated from eroding gullies and saltated onto the uplands along with loess that fell more widely. Sands saltating to the west of the Flats may have entrained some silts, facilitating loessfall downwind. At most sites, the loamy mantle gets increasingly silty near the surface, suggesting that saltation ended before loess deposition.

      PubDate: 2017-06-12T03:03:11Z
      DOI: 10.1016/j.aeolia.2017.05.005
       
  • Terrestrial subaqueous seafloor dunes: Possible analogs for Venus
    • Authors: Lynn D.V. Neakrase; Martina Klose; Timothy N. Titus
      Abstract: Publication date: Available online 5 April 2017
      Source:Aeolian Research
      Author(s): Lynn D.V. Neakrase, Martina Klose, Timothy N. Titus
      Dunes on Venus, first discovered with Magellan Synthetic Aperture Radar (SAR) in the early 1990s, have fueled discussions about the viability of Venusian dunes and aeolian grain transport. Confined to two locations on Venus, the existence of the interpreted dunes provides evidence that there could be transportable material being mobilized into aeolian bedforms at the surface. However, because of the high-pressure high-temperature surface conditions, laboratory analog studies are difficult to conduct and results are difficult to extrapolate to full-sized, aeolian bedforms. Field sites of desert dunes, which are well-studied on Earth and Mars, are not analogous to what is observed on Venus because of the differences in the fluid environments. One potentially underexplored possibility in planetary science for Venus-analog dune fields could be subaqueous, seafloor dune fields on Earth. Known to the marine geology communities since the early 1960s, seafloor dunes are rarely cited in planetary aeolian bedform literature, but could provide a necessary thick-atmosphere extension to the classically studied aeolian dune environment literature for thinner atmospheres. Through discussion of the similarity of the two environments, and examples of dunes and ripples cited in marine literature, we provide evidence that subaqueous seafloor dunes could serve as analogs for dunes on Venus. Furthermore, the evidence presented here demonstrates the usefulness of the marine literature for thick-atmosphere planetary environments and potentially for upcoming habitable worlds and oceanic environment research program opportunities. Such useful cross-disciplinary discussion of dune environments is applicable to many planetary environments (Earth, Mars, Venus, Titan, etc.) and potential future missions.

      PubDate: 2017-04-11T11:50:50Z
      DOI: 10.1016/j.aeolia.2017.03.002
       
  • Leonard Horner and an enthusiasm for Loess
    • Authors: Ian Smalley; Holger Kels
      Abstract: Publication date: Available online 5 April 2017
      Source:Aeolian Research
      Author(s): Ian Smalley, Holger Kels
      Leonard Horner (1785–1864) made substantial contributions to the study of loess. He made field trips with J.J. Noeggerath and Charles Lyell and published useful material on the loess near Bonn. He was an unappreciated pioneer- he was the first person to direct attention to loess as a material. He pointed out that loess was intrinsically interesting. He studied the material transported by the Rhine, and the alluvial deposits in Egypt, looking for links to loess, and the problem of loess formation. He was born in Edinburgh in 1785 and directed the thoughts of young Charles Darwin towards science when he came to Edinburgh to study medicine. Circumstances placed him in Bonn in the critical years 1831–1833; in this time Charles Lyell married his eldest daughter Mary; and both Lyell and Horner encountered the loess. Lyell made it well known via vol.3 of the Principles of Geology, Horner became a loess enthusiast. In the summer of 1833 Horner & Lyell were in the crater of the Roderberg considering the more than 20m of loess deposited there. His major paper was published in 1836 (reporting the Roderberg excursion) and he joined Lyell’s list of loess investigators in the 5th edition of the Principles published in 1837. He was the last to join that select eleven: Bronn, Leonhard, Boue, Voltz, Steininger, Merian, Rozet, Hibbert, Noeggerath, von Meyer, Horner. Most of these were writing on the geology and landscapes of the Rhine valley, but Horner was drawing attention to the amazing nature of the loess itself, in particular the spectacular disaggregation on contact with water. He also published the first geological map of the Bonn region, including the Roderberg and the Siebengebirge, a region of loess and volcanoes.

      PubDate: 2017-04-11T11:50:50Z
      DOI: 10.1016/j.aeolia.2017.03.004
       
  • Development of large nebkhas along an accreting macrotidal coastline,
           Northern France
    • Authors: Marie-Hélène Ruz; Arnaud Héquette; Denis Marin
      Pages: 1 - 14
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Marie-Hélène Ruz, Arnaud Héquette, Denis Marin
      Very large isolated nebkhas, up to 4m high and 14m wide, have developed on the upper beach of a several hundred meters wide foreshore on the French coast of the Dover Strait. This macrotidal shoreline is characterized by abundant sediment supply from the shoreface related to the onshore welding of a nearshore sand bank. Continuing beach accretion provided the conditions for rapid seaward development of incipient foredunes. The nebkhas developed on the uppermost beach, slightly above the highest astronomical tide limit, forming hemispheric to oval-shaped mounds only reached by spring tides and/or storm surges. They do not form an incipient foredune zone, but mounds that grew vertically and remained in the form of isolated huge nebkhas disconnected from the incipient foredune zone by a swale. The nebkhas consist of scattered landforms that do not impede aeolian accretion landward in the incipient foredune zone where the maximum accretion rates were recorded. The distribution of such large coastal nebkhas is probably limited in beach environments since the descriptions of similar examples of aeolian coastal landforms are virtually absent in the scientific literature, suggesting that they are presumably restricted to low gradient macrotidal beaches associated with an excess of sand supply.
      Graphical abstract image

      PubDate: 2016-12-13T10:21:05Z
      DOI: 10.1016/j.aeolia.2016.11.002
      Issue No: Vol. 24 (2016)
       
  • Dust emission and transport over Iraq associated with the summer Shamal
           winds
    • Authors: D. Bou Karam Francis; C. Flamant; J.-P. Chaboureau; J. Banks; J. Cuesta; H. Brindley; L. Oolman
      Pages: 15 - 31
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): D. Bou Karam Francis, C. Flamant, J.-P. Chaboureau, J. Banks, J. Cuesta, H. Brindley, L. Oolman
      In this study, we investigate the diurnal evolution of the summer Shamal wind (a quasi-permanent low-level northwesterly wind feature) and its role in dust emission and transport over Iraq, using ground-based and space-borne observations together with a numerical simulation performed with the mesoscale model meso-NH. A 6-year dataset from the synoptic stations over Iraq allows establishing the prominence of the link between strong near surface winds and reduced visibility in the summer. The detailed processes at play during Shamal events are explored on the basis of a meso-NH simulation for a given, representative case study (25 June–3 July 2010). The Shamal exhibits an out-of-phase relationship between the surface wind and winds in the lower troposphere (typically 500m above ground level), the maximum surface wind speeds being observed during the day while in altitude the maximum wind speeds are observed at night. The daytime near surface winds, at the origin of dust emission, are associated with the downward transfer of momentum from the nocturnal low-level jet to the surface due to turbulent mixing after solar heating commences each day. For the first time, an estimate of the dust load associated with summer Shamal events over Iraq has been made using aerosol optical depths derived from the Spinning Enhanced Visible and Infrared Imager, the Moderate Resolution Imaging Spectroradiometer, and the simulation. The dust load exhibits a large diurnal variability, with a daily minimum value of 1Tg around 0600UTC and a daily peak of 2.5Tg or more around 1500UTC, and is driven by the diurnal cycle of the near surface wind speed. The daily dust load peak associated with the summer Shamal over Iraq is in the same order of magnitude as those derived from simulations downstream of the Bodélé depression in Chad, known to be the world’s largest dust source.

      PubDate: 2016-12-13T10:21:05Z
      DOI: 10.1016/j.aeolia.2016.11.001
      Issue No: Vol. 24 (2016)
       
  • Abrasion resistance of muscovite in aeolian and subaqueous transport
           experiments
    • Authors: Calvin J. Anderson; Alexander Struble; John H. Whitmore
      Pages: 33 - 37
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Calvin J. Anderson, Alexander Struble, John H. Whitmore
      Complementary aeolian and subaqueous transport experiments showed a trend in muscovite abrasion that may be useful for identifying ancient sandstones as aeolian or subaqueous in origin. We found that our experimental aeolian processes pulverized the micas quickly, while our subaqueous processes did not. In a pair of abrasion resistance experiments conducted with micaceous quartz sand, it was found that large muscovite grains were (1) reduced by aeolian processes to less than 500μm in just 4days, and (2) preserved by subaqueous processes to 610±90μm even after 356days. At 20days of aeolian transport no loose micas could be found even under the microscope, but after a year of subaqueous transport loose muscovite grains could still be seen with the naked eye. Thus, the occurrence and character of micas in a sandstone, particularly muscovite, may be helpful in determining the ancient depositional process.

      PubDate: 2016-12-21T10:27:31Z
      DOI: 10.1016/j.aeolia.2016.11.003
      Issue No: Vol. 24 (2016)
       
  • An Israeli haboob: Sea breeze activating local anthropogenic dust sources
           in the Negev loess
    • Authors: Onn Crouvi; Uri Dayan; Rivka Amit; Yehouda Enzel
      Pages: 39 - 52
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): Onn Crouvi, Uri Dayan, Rivka Amit, Yehouda Enzel
      Meso-scale weather systems, such as convective haboobs, are considered to be an important dust generation mechanism. In Israel, however, rather than of meso-scale weather systems, most dust storms are generated by synoptic-scale systems, originating from Sahara and Arabia. Consequently, only distal sources of suspended and deposited dust in Israel are currently reported. Here we report the first detailed study on the merging of synoptic- and meso-scale weather systems leading to a prominent dust outbreak over the Negev, Israel. During the afternoon of May 2nd, 2007, a massive dust storm covered the northern Negev, forming a one kilometer high wall of dust. The haboob was associated with PM10 concentrations of 1000–1500μgm−3 that advanced at a speed of 10–15ms−1 and caused temporary closure of local airports. In contrast to most reported haboobs, this one was generated by a sea breeze front acting as a weak cold front enhanced by a cold core cyclone positioned over Libya and Egypt. The sea breeze that brought cold and moist marine air acted as a gravity current with strong surface winds. The sources for the haboob were the loessial soils of the northwestern Negev, especially agricultural fields that were highly disturbed in late spring to early summer. Such surface disturbance is caused by agricultural and/or intensive grazing practices. Our study emphasizes the importance of local dust sources in the Negev and stresses loess recycling as an important process in contemporary dust storms over Israel.
      Graphical abstract image

      PubDate: 2016-12-21T10:27:31Z
      DOI: 10.1016/j.aeolia.2016.12.002
      Issue No: Vol. 24 (2016)
       
  • Desert dust hazards: A global review
    • Authors: N.J. Middleton
      Pages: 53 - 63
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): N.J. Middleton
      Dust storms originate in many of the world’s drylands and frequently present hazards to human society, both within the drylands themselves but also outside drylands due to long-range transport of aeolian sediments. Major sources of desert dust include the Sahara, the Middle East, central and eastern Asia, and parts of Australia, but dust-raising occurs all across the global drylands and, on occasion, beyond. Dust storms occur throughout the year and they vary in frequency and intensity over a number of timescales. Long-range transport of desert dust typically takes place along seasonal transport paths. Desert dust hazards are here reviewed according to the three phases of the wind erosion system: where dust is entrained, during the transport phase, and on deposition. This paper presents a synthesis of these hazards. It draws on empirical examples in physical geography, medical geology and geomorphology to discuss case studies from all over the world and in various fields. These include accelerated soil erosion in agricultural zones – where dust storms represent a severe form of accelerated soil erosion – the health effects of air pollution caused by desert aerosols via their physical, chemical and biological properties, transport accidents caused by poor visibility during desert dust events, and impacts on electricity generation and distribution. Given the importance of desert dust as a hazard to human societies, it is surprising to note that there have been relatively few attempts to assess their impact in economic terms. Existing studies in this regard are also reviewed, but the wide range of impacts discussed in this paper indicates that desert dust storms deserve more attention in this respect.

      PubDate: 2016-12-28T10:32:28Z
      DOI: 10.1016/j.aeolia.2016.12.001
      Issue No: Vol. 24 (2016)
       
  • Analysis of an optical gate device for measuring aeolian sand movement
    • Authors: V. Etyemezian; G. Nikolich; W. Nickling; J.S. King; J.A. Gillies
      Pages: 65 - 79
      Abstract: Publication date: February 2017
      Source:Aeolian Research, Volume 24
      Author(s): V. Etyemezian, G. Nikolich, W. Nickling, J.S. King, J.A. Gillies
      Movement of sand in response to wind is the most important feature of aeolian sediment transport on Earth and other planets. Through sand blasting during saltation, large amounts of dust are ejected into the atmosphere and transported long distances, impacting climate and human health. Despite continuing improvements, currently available devices for field measurement of sand movement have limitations. An optical gate device (OGD) for detecting the movement, size, and possibly speed of individual sand grains during aeolian sediment transport was analyzed. The approach uses the highly time resolved signal from these sensors, which consist of a light emitter and a photosensitive sensor. A specific OGD that is manufactured by Optek (Carrollton, Texas, USA) was tested in a sediment transport wind tunnel alongside trap-style devices. The OGD device provided particle counts and total signal response that were well correlated with sand trap data (R2 between 0.66 and 0.88). Inter-comparison among eight identical units of the OGD showed excellent repeatability (R2 >0.98 for 7 of 8 units). Subsequent tests revealed that the response of the phototransistor (light sensor) can be linear when operated within certain workable limits. Practical implications of this are that there is potential for extracting size distribution information. Limits imposed by noise levels in the signal and interferences from extraneous light sources were also identified. Despite the results presented being specific to the OGD model tested, much of the approach outlined is applicable to any OGD-type device (including Wenglor®) if the signal of the photo detector can be accessed directly.

      PubDate: 2016-12-28T10:32:28Z
      DOI: 10.1016/j.aeolia.2016.11.005
      Issue No: Vol. 24 (2016)
       
  • Our evolving understanding of aeolian bedforms, based on observation of
           dunes on different worlds
    • Authors: Serina Diniega; Mikhail Krevalevsky; Jani Radebaugh; Simone Silverstro; Matt Telfer; Daniela Tirsch
      Abstract: Publication date: Available online 24 October 2016
      Source:Aeolian Research
      Author(s): Serina Diniega, Mikhail Krevalevsky, Jani Radebaugh, Simone Silverstro, Matt Telfer, Daniela Tirsch
      Dunes, dune fields, and ripples are unique and useful records of the interaction between wind and granular materials – finding such features on a planetary surface immediately suggests certain information about climate and surface conditions (at least during the dunes’ formation and evolution). Additionally, studies of dune characteristics under non-Earth conditions allow for “tests” of aeolian process models based primarily on observations of terrestrial features and dynamics, and refinement of the models to include consideration of a wider range of environmental and planetary conditions. To-date, the planetary aeolian community has found and studied dune fields on Mars, Venus, and the Saturnian moon Titan. Additionally, we have observed candidate “aeolian bedforms” on Comet 67P/Churyumov-Gerasimenko, the Jovian moon Io, and – most recently – Pluto. In this paper, we hypothesize that the progression of investigations of aeolian bedforms and processes on a particular planetary body follows a consistent sequence – primarily set by the acquisition of data of particular types and resolutions, and by the maturation of knowledge about that planetary body. We define that sequence of generated knowledge and new questions (within seven investigation phases) and discuss examples from all of the studied bodies. The aim of such a sequence is to better define our past and current state of understanding about the aeolian bedforms of a particular body, to highlight the related assumptions that require re-analysis with data acquired during later investigations, and to use lessons learned from planetary and terrestrial aeolian studies to predict what types of investigations could be most fruitful in the future.

      PubDate: 2016-10-25T11:20:54Z
      DOI: 10.1016/j.aeolia.2016.10.001
       
  • Aeolian dune sediment flux heterogeneity in Meridiani Planum, Mars
    • Authors: Matthew Chojnacki; Anna Urso; Lori K. Fenton; Timothy I. Michaels
      Abstract: Publication date: Available online 5 October 2016
      Source:Aeolian Research
      Author(s): Matthew Chojnacki, Anna Urso, Lori K. Fenton, Timothy I. Michaels
      It is now known unambiguously that wind-driven bedform activity is occurring on the surface of Mars today, including early detections of active sand dunes in Meridiani Planum’s Endeavour crater. Many of these reports are only based on a few sets of observations of relatively isolated bedforms and lack regional context. Here, we investigate aeolian activity across central Meridiani Planum and test the hypothesis that dune sites surrounding Endeavour crater are also active and part of region-wide sediment migration driven by northwesterly winds. All 13 dune fields investigated clearly showed evidence for activity and the majority exhibited dune migration (average rates of 0.6m/Earth-year). Observations indicate substantial geographic and temporal heterogeneity of dune crest fluxes across the area and per site. Locations with multiple time steps indicate dune sand fluxes can vary by a factor of five, providing evidence for short periods of rapid migration followed by near-stagnation. In contrast, measurements at other sites are nearly identical, indicating that some dunes are in a steady-state as they migrate. The observed sediment transport direction was consistent with a regional northeasterly-to-northwesterly wind regime, revealing more variations than were appreciated from earlier, more localized studies. Craters containing shallow, degraded, flat-floored interiors tended to have dunes with high sediment fluxes/activity, whereas local kilometer-scale topographic obstructions (e.g., central peaks, yardangs) were found to be inversely correlated with dune mobility. Finally, the previous, more limited detections of dune activity in Endeavour crater have been shown to be representative of a broader, region-wide pattern of dune motion.

      PubDate: 2016-10-11T17:48:41Z
      DOI: 10.1016/j.aeolia.2016.07.004
       
  • The albedo of martian dunes: Insights into aeolian activity and dust devil
           formation
    • Authors: K.A. Bennett; L. Fenton; J.F. Bell
      Abstract: Publication date: Available online 10 September 2016
      Source:Aeolian Research
      Author(s): K.A. Bennett, L. Fenton, J.F. Bell
      Wind is the primary geologic process currently active on the surface of Mars. Albedo variations at eight dune fields were tested based on the hypothesis that a dune’s ripple migration rate is correlated to its albedo. On Mars, where the atmospheric pressure is low, dust is removed from the surface of a dune by saltating sand. Therefore, more active dunes should remove dust more efficiently than less active dunes. A dune’s albedo was found to be low in the first half of the Mars year (Ls =0–180°) and high in the second half (Ls =180–360°) during the dusty season. Both dunes with fast- and slow-moving ripples exhibit low albedos, whereas dunes with ripples that migrate at intermediate speeds exhibit high albedos. A dune’s minimum albedo does not have a simple correlation with its ripple migration rate. Instead, we propose that dust devils remove dust on slow-moving and immobile dunes, whereas saltating sand caused by strong winds removes dust on faster dunes. Albedo should not be used as a proxy for migration rate of ripples or dune activity, as it may be difficult to distinguish between fast- and slow-moving ripples on dunes that have the same albedo. The presence of dust devil tracks on a dune could indicate the dune and/or its ripples are either immobile or migrating slowly. We also propose that albedo variations on individual dune fields can reveal insight into the local wind regime.

      PubDate: 2016-09-17T17:07:59Z
      DOI: 10.1016/j.aeolia.2016.08.009
       
 
 
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